1. Field of the Invention
The present invention relates generally to the conveyance of unstable, empty containers in a production line, and more particularly to a transfer stabilization support that temporarily attaches to a top-heavy or odd-shaped container with a non-round bottom surface end so that the top-heavy or odd-shaped container can be easily conveyed throughout the production line.
2. Related Art
Typically, containers are formed with a stable base surface so that the containers can easily be conveyed in a table-top fashion along a production line. Generally, containers are moved freely through a production line by standing the container on its base surface and pushing the container via air along the production line. The production line may start when the container exits the container forming operation and continue to filling and capping operations and then to a cooling operation, if necessary. However, the shape of some of the containers do not lend themselves to be conveyed along a production line in the table-top fashion.
Some containers may have a narrower bottom end than an upper end of the container. The wider upper portion and the narrower bottom end, while having a relatively smooth surface, produce a container that cannot be easily conveyed when the container is empty, because the upper end produces a top-heavy empty container that may topple over on its side when the container is pushed via air or other means. Similarly, long slender containers typically have poor line conveyance due to a high center of gravity. While conventional hot-fill technology incorporates a number of recessed panels that are placed in the mid-section of the container, emerging technologies in the hot-fill area are producing hot-filled containers with a vacuum absorption panel, which is recessed, at the lower third of the container. That is, the recessed panel is being moved to the lower third of the container resulting in a containers being formed with a slender lower or standing portion, which tends to tip over when being pushed by air, for example, when being guided to a conveyor in a table-top production line. An empty top-heavy container can result also from “light-weighting” the base and sidewalls of a container to reduce the cost of the container since the finish area of the container retains its weight in grams of plastic material in order to provide integrity for the closure. Other containers may have a substantially rounded base or a projection extending outward from a bottom end of the container, which inhibits the conveying of the container in the least expensive production line (i.e., a table-top conveying system).
Thus, such odd-shaped containers either cannot be conveyed in the table-top fashion, or their conveyance in a table-top fashion results in numerous toppled containers and requires costly, constant supervision to facilitate the movement of the containers through the production line. Consequently, a complex system of conveyors was thought necessary in order to convey the odd-shaped container through the filling, capping, batching and cooling operations. Such a complex system of conveyors for a production line is a costly investment since it may only be useful for a single odd-shaped container.
In order to provide lightweight (and less costly) containers, it is known in the art to remove the gram weight out of the sidewalls and bottom of the containers. However, this method adds to the instability of the formed lightweight container, as it is conveyed in a conventional table-top system, as the center of gravity moves upwards as gram weight is removed from the bottom and sidewalls of the container resulting in a container that is easier to tip over. This trend for lightweight containers and the trend to move the vacuum compression panels to the lower third of the container presents a challenge in conveying the new containers in a cost-efficient manner.
A complex conveying system involving rails that hold the containers by their necks can handle containers that tend to topple over when pushed or controlled by air in a table-top conveying system. While neck conveying guide rails may be suitable for conveying some containers along a portion of a production line, the neck rail conveyor is not suitable for entry into a cooling tunnel and exiting therefrom, as a cost-effective, cooling operation is typically achieved by cooling a number of the containers at one time.
Moreover, a rail neck conveying system is designed only for containers having substantially the same neck size. Accordingly, reliance on a rail neck conveying system would involve such inefficiencies as changing the entire rail neck conveying system to enable the conveying of a different type of container, such as a container with a different sized neck. This would result in an unacceptable level of downtime and would limit the design of containers used by this specialized rail device to a small number of containers.
Consequently, what is needed is a process for conveying top-heavy and odd-shaped containers in a cost-effective manner. This is especially true for conveying containers that are to be filled with a hot product and then are cooled in a production line. In order for these containers to be conveyed in the table-top fashion in a production line (e.g., from the blow-molded stage, where the container is formed to a capping and filing operation), a temporary transfer stabilization support is needed.